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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #343901

Research Project: Emerging and Invasive Nematode and Virus Pathogens Affecting Potato

Location: Emerging Pests and Pathogens Research

Title: Phylogenetic study of recombinant strains of Potato virus Y

item GREEN, KELSIE - University Of Idaho
item BROWN, CELESTE - University Of Idaho
item Gray, Stewart
item KARASEV, ALEXANDER - University Of Idaho

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2017
Publication Date: 7/1/2017
Citation: Green, K.J., Brown, C.J., Gray, S.M., Karasev, A.V. 2017. Phylogenetic study of recombinant strains of Potato virus Y. Virology. 507:40-52.

Interpretive Summary: New strains of Potato virus Y have been rapidly emerging and expanding their geographical range in the past decade. These new strains are more difficult to manage and cause a tuber necrotic disease which reduces the quality of the potato and impacts trade. This study compared the genome sequences and biological characteristics of nearly 300 PVY isolates across the spectrum of strains to investigate genome diversity and evolution. It was discovered that most of the new strains contain genetic material from two strains of the virus that were prevalent in potato during the 1900s. The genetic diversity within strains is exceptionally high and suggests that virus recombination is the primary means of PVY evolution. Additionally, the present strains evolved through many different recombination events and will likely continue to evolve new strains. The ability of the new strains to outcompete the old strains suggests that the recombining viruses are more fit than their parents.

Technical Abstract: Potato virus Y (PVY) exists as a complex of strains, including a growing number of recombinants. Evolution of PVY proceeds through accumulation of mutations and more rapidly through recombination. Here, the role of recombination in PVY evolution and the origin of common PVY recombinants were studied through whole genome analysis of 119 newly sequenced PVY isolates largely from U.S. potato, and subsequent combined phylogenetic and recombination analyses with an additional 166 whole PVY genomes from the GenBank database. Two novel PVYC recombinants were sequenced and identified, along with one novel PVYN:O recombinant. Sequence diversity in the parental sequences made it possible to trace the origins of all recombinant types of PVY, which also showed remarkable sequence diversity in most cases. The results suggested that the common recombinant PVY strains originated more than once, from different parental sequences.